This plant has a very short flowering period after which it virtually disappears without trace. It can be cleistogamous which means that it doesn't have to open the flowers in order for self-pollination and seed setting to take place. It has been known from this site for over twenty years to my knowledge but is, according to Stace reducing in numbers.

It is found most often in East Anglia and Southern coastal regions of England but far less frequently in the North of England, Scotland and there is very little in Ireland.